This article deals with blood flow and tissue pressure changes in the inflamed dental pulp. While detailed patho-physiological studies of the circulation in the inflamed pulp are still partly lacking, available data from studies of the normal pulp tissue are also discussed. Knowledge of the normal physiological adjustments may indicate which circulatory changes would take place during inflammation. One of the focal points in the present article is how a localized increased tissue pressure may persist in the inflamed area without a circumferential spread to the rest of the pulp. The article is organized in the following manner: First a short review is given of the vascular changes during inflammation in general. Then available data from morphological and functional studies of the pulpal circulation are treated in some detail. Particular attention is given to the transcapillary fluid flow and the so-called‘self-strangulation theory’. The effect of a localized increased tissue pressure on pulpal blood flow is thereafter discussed.